Air valve structure for hammer mill

ABSTRACT

AN AIR VALVE STRUCTURE IN CONNECTION WITH A GRINDING MILL TO CONTROL THE RECIRCULATION OF AIR THEREIN AND THE ADMISSION OF AIR THERTO. SAID AIR VALVE STRUCTURE CONSISTS OF A PAIR OF CYLINDRICAL MEMBERS WITH ONE BEING DISPOSED WITHIN THE OTHER AND WITH EACH HAVING A PLURALITY OF VENTS CIRCUMFERENTIALLY SPACED THERABAOUT, SAID MEMBERS BEING ROTATABLY MOVABLE RELATIVE TO ONE ANOTHER TO POSITION THEIR RESPECTIVE VENTS IN DIFFERENT DEGREES OF REGISTRATION WITH ONE ANOTHER TO CONTROL THE RECIRCULATION OF AIR WITHIN THE GRINDING CHAMBER AND SAID VALVE STRUCTURE EXTENDS OUTWARDLY OF SAID MILL AND HAS MEANS THEREIN TO CONTROL THE PASSAGE OF OUTSIDE AIR THERETHROUGH TO SAID GRINDING CHAMBER.

14, 1972 H. c. JACOBSON AIR VALVE STRUCTURE FOR HAMMER MILL 2 Sheets-Sheet 1 Filed Aug. 23, 1971 m umh f w llllllll Mill INVENTOR.

Nov. 14, 1972 H. c. JACOBSON 3,702,636

AIR VALVE STRUCTURE FOR HAMMER MILL Filed Aug. 25, 1971 2 Sheets-Sheet 2 FIG; .5 I

l I I INVENTOR. FIE: 4 AOIWYIPD C. .J'wcoBso/v United States Patent Oifice 3,702,686 Patented Nov. 14, 1972 US. Cl. 24159 Claims ABSTRACT OF THE DISCLOSURE An air valve structure in connection with a grinding mill to control the. recirculation of air therein and the admission of air thereto. Said air valve structure consists of a pair of cylindrical members with one being disposed within the other and with each having a plurality of vents circumferentially spaced thereabout, said members being rotatably movable relative to one another to position their respective vents in different degrees of registration with one another to control the recirculation of air within the grinding chamber and said valve structure extends outwardly of said mill and has means therein to control the passage of outside air therethrough to said grinding chamber.

BACKGROUND AND SUMMARY OF THE INVENTION A grinding mill traditionally is a piece of apparatus having general utility for grinding feed products. This type of apparatus has developed significant usefulness in grinding a general variety of materials having industrial application. Many materials which are ground require only a recirculation of air through the grinding chamber. Many industrial applications of grinding have been found to require a control of the quality of air admitted to the grinding chamber with respect to humidity content and some materials require the presence of particular chemical properties. Some products which are ground require clean air in the grinding chamber. Some products require a controlled flow of air through the grinding chamber. Hence, control of air flow as well as control of the quality of air into the grinding chamber has achieved significant importance in this art.

It is an object of this invention therefore, to provide means to control both the quality and the quantity of air flowing through the grinding chamber of a grinding mill.

It is another object of this invention to provide means to control both the recirculation of air within the grinding chamber of a grinding mill and to control the admission of outside air into said grinding chamber. Generally stated the invention herein comprises an air valve structure consisting of a pair of cylindrical members with one being disposed within the other and said cylindrical members having rotatable movement relative to one another, vents circumferentially disposed about each of said members, means adjusting the relative positions of one of said members with respect to the other for different degrees of registration of said vents to control the recirculation of air, said valve structure having communication with an outside supply of air and means within said valve structure controlling the admission of said outside air to said grinding chamber.

These and other objects and advantages of the invention will be set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

FIG. 1 is a broken view in elevation of a grinding mill with a portion thereof being shown in dotted line;

FIG. 2 is a broken view in vertical section taken on line 2-2 of FIG. 1 as indicated;

FIG. 3 is a broken view on an enlarged scale in vertical section taken on line 3-3 of FIG. 2. as indicated; and FIG. 4 is an exploded view in perspective of a detail of structure with portions thereof being broken away.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to the drawings, a grinding mill 10 is indicated comprising generally a feed supply or material supply chamber 12 and a grinding chamber 14. The invention herein relates more directly to the grinding chamber. Only so much of the structure of said mill is shown as is believed necessary to support a description of structure and function of the invention herein.

A Wall 17 is disposed intermediate said supply and grinding chambers. Said grinding chamber as shown comprises side walls 19 and 20, a curved top wall 21, and a bottom wall 22, and a front wall 24. Extending outwardly of said front wall 24 is a flange 25 defining a door opening 26. Overlying said door opening and said flange portion is a door 29 hinged to said side wall 20 by a suitable hinge 31. Said door will be secured by conventional cam type lock members 3-2 which will have portions underlying said front wall 24 as shown.

Said grinding chamber 14 includes a shaft 35 disposed through an opening 36 formed in said wall 17 and said shaft supports a hub member 39' within said grinding chamber. Said hub member will have hammers 41 mounted thereon.

Projecting forwardly of said wall 17 is an upper bracket 43 in the form of an angled bar and which supports a screen 47 shown here as a tear drop in form and having one side thereof disposed against said wall 17 and about a flange 44 carried by said wall. Overlying the open front side of said screen is a screen plate 50 of somewhat larger size than said screen and having an annular flange 52 adapted to be disposed inwardly of said screen to provide support. Said screen plate 50 has a central opening 53 therein. Within said screen is a screen chamber 54.

Said door 29 is shown having inwardly projecting stud members 57 tapped to receive bolts 59 passing through accommodating holes in said screen plate member 50.

Said door 29 and said screen plate 50 are held in locked engagement by the bolts 59 and carried therebetween is the air valve structure 60 which comprises the subject matter of the invention herein.

Said air valve structure 60 consists of a pair of members 62 and 64 cylindrical in form and being operatively related with the member 64 being disposed within and through member 62.

Said member 62 comprises a bod portion 63 having an annular rear flange rim 66 flush with the adjacent end of said body portion and at right angles to the axis thereof and a like front flange rim 67 set back somewhat from the forward end of said body portion leaving a forwardly projecting body portion 68. Said body portion 63 has a plurality of longitudinal slots or vents 70' therein extending between said rim portions. Said vents which may vary in width and number are shown as being four in number having width the same as the width of the separating body portions therebetween.

The rim 67 has spaced holes 71 aligned with corresponding holes 73 in the door 29 to receive bolts 75 therethrough and said door has an opening 77 therein to receive the body portion 68 therein.

The member 64 consists of a body portion 80 having an annular flange rim 81 flush with the rear end thereof and at right angles to the axis thereof. Said body portion 80 has a greater length than said body portion 63 and has a diameter such as to permit it to be disposed through said body portion 63. Said body portion 80 has a plurality of longitudinal vents 82 therein corresponding to said vents '70. Said. wallv50 .has an opening 84.therein corresponding in size to the internal diameter of said body portion 80.

In operating position, the member 64. in being disposed through the member 62 will have the forward portion 80a thereof projected outwardly of said door 29. The inner edge portion 80b of said body 80 will underly the body portion 68. Carried at said inner edge portion 80b and threaded therethrough is a wing bolt 85. A nut 86 may be secured to said portion 80b to provide a greater depth through which said bolt 85 may be threatened. Said wing bolt in being rotated will bear against the-adjacent body portion 68 to lookingly engage said members 64. and 62.

Carried within said body portion 80a is a damper 90 within a damper opening or passage 91. Said damper is circular in form and supported between a pair of diametrically disposed bifurcated holding members 93 and 96. Said member 93 comprises an externally threaded pin having a slotted or bifurcated head portion 94 disposed through an accommodating aperture 98 and having an edge portion of said damper seated thereinto. Said damper and said pin may be secured together as by welding. A lock nut 95 is threaded onto said pin.

The holding member 96 comprises an angled pin having a right angled handle portion 97 and a threaded shank portion 99 disposed through an accommodating aperture 100 in said body portion 80a and having a bifurcated shank end portion 101 into which is received an adjacent edge portion of said damper to be secured therein as by welding. A locking nut 102 is threaded onto said shank outwardly of said body portion to bear against said body portion 80a.

In FIG. 2, a broken portion of a conduit 104 is shown to indicate, if desired, a removable connection to a controlled source of air such as humidified, chemically treated or cleaned air as an alternative to the ambient air present in the atmosphere about the hammer mill.

OPERATION In the conventional operation of a hammer mill, the grinding chamber includes therein an inner chamber formed in part or in whole by a screen within which material is ground and sifted through the screen. There is a continuous recirculation of air from within the screen chamber outwardly into and through the grinding chamber. The screen chamber generally has an axial open ing for the return air. The air may also be exhausted from the grinding chamber.

The invention herein provides means to control the recirculation of air and in addition to provide for the entry of outside air such as ambient air or air from a controlled source.

A large variety of materials are groundin a hammer mill. Some materials to be suitably ground require the presence of heated air or cooled air. Some may require a particular c'hemical content in the air, and some materials may require the presence of clean air. Some products require a very minimal air supply in which case outside air may be cut off.

With respect to the control of the recirculation of air, the return air to the screen chamber enters through the air valve structure 60 and more particularly through the vents 70 and 82. The maximum opening of the vents is present when said vents are in register with each other. To adjust the vent openings, the wing bolt '85 is loosened to permit movement by hand of the member 64. When the vent spacing is adjusted as desired by the operator, said wing bolt is tightened to lock the members 62 and 64 together. Said bolt extends through the member '64 to bear against the inner wall surface of the member 62. The member 64 may be rotated by reaching the hand past the damper 90 in opened position using the wing bolt 85 for a turning handle.

The entry of outsideair is readily controlled by the positioning of the damper 90, the operation of which is believed to be clear from the description given.

It will be understood that, as shown, with the conduit 104 removed that ambient air will pass through the damper opening 91 into the screen chamber 54. However, as shown, an appropriate conduit 104 can readily be extended from a controlled air or gas supply, said damper opening to provide whatever kind or quality of air or gas may be desired with respect to the particular material being ground within the screen chamber.

Hence there is here provided an improvement to a hammer mill structure which relates directly to the control of air into the grinding chamber.

It will be understood of course that various changes may be made in form, details, arrangement and proportions of the parts without departing from the scope of the invention herein which, generally stated, consists in an apparatus capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

1. In a hammer mill structure including a grinding chamber having a screen member therein forming a screen chamber whereby air reciroulates from said screen chamber through said grinding chamber having in combination an outer wall of said grinding chamber,

a plate member overlying said screen chamber in spaced relation to said outer wall,

said plate member having a passage therethrough into said screen chamber for passage of air from said grinding chamber, said outer wall having a passage therethrough aligned with said passage through said plate member,

an air valve structure disposed between said plate member and said outer wall having a passage therethrough aligned with said passage through said outer wall and said passage through said plate member for communication of outside air with said screen chamber,

means carried by said valve structure adjusting said passage therethrough to control the passing of outside air into said screen chamber,

said valve structure having transverse vents therein, said vents permitting the passage of air from said grinding chamber into said screen chamber, and

'means carried by said valve structure adjusting said vents.

2. The structure set forth in claim 1 wherein said outer wall comprises a door, and

means securing said valve structure to said door.

3. The structure set forth in claim 1, wherein said valve structure comprises a pair of cylindrical members having one disposed within the other to be rotatably movable therein for adjusting said vents.

4. The structure set forth in claim 1, wherein said valve structure has a portion thereof extending through said outer wall,

said passage adjusting means comprises a damper disposed within said extruded portion, and

means adjusting said damper.

5. The structure set forth in claim 1, wherein said outer wall comprises a door,

means securing said plate member to said door,

said valve structure being carried by said door integrally with said plate member.

References Cited UNITED STATES PATENTS 2,100,200 11/1937 Mosley 241 -59 X 2,522,027 9/1950 Evans 24l--59 X 3,313,494 4/1967 Peterson 24159 X GRANVILLE Y. CUST ER, JR., Primary Examiner 

